It’s been revealed Samantha Cameron warned her husband earlier that “the ‘it’s beneath me to comment’ thing is really not going to fly at the dinner table tonight.”

Number 10 has worked hard today not to engage with allegations that the Prime Minister placed his member into the mouth of a decapitated pig’s head as a student, but Mrs Cameron told a friend that the allegations “would be coming up” and that there “would be repercussions” in the event of an unsatisfactory response.

The story, which surfaced in a book by the PM’s former colleague (now arch-nemesis) Lord Ashcroft, links Cameron to an act of dead-pig face-sex during a ritual at the Piers Galveston dining society – an allegation that pigs everywhere have described as “incredibly insulting.”

A family-friend who was with Samantha this morning as the allegations were announced on the news said “Sam’s jaw dropped, and she shouted ‘He did what?!‘

“I said ‘Oh come on, Sam; the news is full of bullshit’ but she shot me this dark ‘you have no idea what Dave is capable of’ look, so I changed the channel whilst she stormed into the kitchen and began throwing crockery at the wall.”

A Westminster source confirmed that the Prime Minister spent the afternoon “approaching colleagues to see if they fancied a few pints after work, in a lame attempt to avoid going home.

“But then he got a phone-call and the blood drained from his shiny face, and he looked like he was going to be sick. He said he had been Summoned, and walked off to the car like a man on his way to the gallows.

“I’d feel more sorry for him if he wasn’t a pig-fucker, but even so, it’s not going to be a fun evening at No. 10 is it?”